fix(cli): use dirname intrinsic in react-vite template (#7062)

apps/wing/project-templates/wing/react-vite/backend/main.w

@@ -4,18 +4,12 @@ bring vite;
 bring http;
 bring "./broadcaster.w" as broadcaster;
 
-// Winglang doesn't have a built-in support for __dirname yet, so we use a workaround to get the current directory.
-// @see tracking issue: https://github.com/winglang/wing/issues/3736
-class Utils {
-  extern "utils.js" pub static __dirname(): str;
-}
-
 let myBroadcaster = new broadcaster.Broadcaster() as "Broadcaster";
 let api = new cloud.Api(cors: true);
 let counter = new cloud.Counter();
 
 let website = new vite.Vite(
-  root: "{Utils.__dirname()}/../frontend",
+  root: "{@dirname}/../frontend",
   publicEnv: {
     TITLE: "Wing + Vite + React",
     API_URL: api.url,